• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.677-683
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• 2005

In this work, the effect of additives such as solvent, sodium dodecyl sulfate and NaCl on microemulsion phase behavior and flux removal efficiency in systems containing commercial alkyl ethoxylates nonionic surfactant was investigated. The addition of a n-hydrocarbon as a solvent produced on O/W (Oil/Water) microemulsion phase over a wider range of temperature and cosurfactant to surfactant ratios. Especially, the addition of n-hexadecane to the surfactant system, which was the most hydrophobic solvent among the solvents used in this study, produced a microemulsion phase over a wide range of temperatures and promoted formation of a microemulsion phase at lower temperatures. The candidate for cleaner samples, prepared from phase behavior experiments, showed excellent removal efficiency for abietic acid at $40^{\circ}C$. These data suggested the potential applicability of hydrocarbons to actual cleaner formulations.

• Geophysics and Geophysical Exploration
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• v.18 no.3
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• pp.143-153
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• 2015

Polymer flooding for enhancing hydrocarbon production injects into a reservoir polymer solution that is viscous. It is very important to monitor the behavior pattern of the polymer solution in order to evaluate the effectiveness of polymer flooding. To monitor the distribution of polymer solution and thus fluid substitution within the reservoir, we first construct seismic and resistivity rock physics models (RPMs), which are functions of reservoir parameters such as rocks and type of fluid, fluid saturation. For the seismic and resistivity RPMs, responses of seismic and electromagnetic (EM) tomography are numerically simulated as polymer injection, using two dimensional (2D) staggered-grid finite difference elastic modeling and 2.5D finite element EM modeling algorithms, respectively. In constructing RPM for EM tomography, three different reservoir rocks are considered: clean-sand, dispersed shale-sand, and sand-shale lamination rocks. The polymer solution is assumed to have 2 wt% of polymer as normally generated, while water is freshwater or saltwater. Further, neutron logging is also considered to check its sensitivity to polymer flooding. The techniques discussed in the paper are important in monitoring not only hydrocarbon but also geothermal reservoirs.

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.969-979
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• 2012

In this study, the effects of cosurfactant on phase equilibrium and dynamic behavior were studied in systems containing nonylphenol ethoxylate (NP) surfactant solutions and nonpolar hydrocarbon oils. All the cosurfactants used during this study such as n-pentanol, n-octanol and n-decanol acted as a hydrophobic additive and the hydrophobic effect was found to increase with both increases in chain length and amount of addition of a cosurfactant. Dynamic behavior studies under hydrophilic conditions showed that the solubilization of hydrocarbon oil by NP micellar solution is controlled by an interface-controlled mechanism rather than a diffusion-controlled mechanism. Both spontaneous emulsification of water into oil phase and expansion of oil drop were observed under lipophilic conditions because of diffusion of surfactant and water into oil phase. Under conditions of a three phase region including a middle-phase microemulsion, both rapid solubilization and emulsification of oil into aqueous solutions were found mainly due to the existence of ultralow interfacial tension.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.455-460
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• 2019

Hydrotreating catalysis refers to a various hydrogenation which saturate an unsaturated hydrocarbon, together with removing heteroatoms such as sulfur, nitrogen, oxygen, and trace metals from different petroleum streams in a refinery. Most refineries include at least three hydrotreating units for upgrading naphtha, middle distillates, gas oils, intermediate process streams, and/or residue. Among them, hydrotreating catalysis for residue are the core of the process, because of its complexity. This article reviews recent progress in tackling the issues found in the upgrading residues by hydrotreating, focusing on the chemistry of hydrodemetallization (HDM) and hydrodesulfurization (HDS). We also discuss the composition and functions of hydrotreating catalysts, and we highlight areas for further improvement.

• Applied Chemistry for Engineering
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• v.28 no.4
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• pp.467-472
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• 2017

In this study, the reforming reaction of vacuum residue (VR) was carried out using aquathermolysis reaction. VR showed a prone to decrease the amount of resins and asphaltenes in the constituents, and to increase saturates and aromatics when reacting with steam at 30 bar and above $300^{\circ}C$ for 24 h. This tendency became more evident when the amount of steam used was excessive than the amount of VR. When the aquathermolysis reaction was performed at $300^{\circ}C$ and 30 bar for 48 h, the VR composition was changed from the initial state (S/A/R/A = 7.3%/43.7%/25.6%/23.5%) to final state (S/A/R/A = 6.8%/57%/12.2%/24.0%), and the contents of the resins decreased by 13% and the aromatic compounds increased by 13%. The viscosity decreased from 880,000 cp to 290,000 cp by 68%. When 10% of decalin, which is easy to provide hydrogen, was added, the viscosity decreased by 68% in 24 h. The VR composition showed a reduction in the contents of resins and asphaltenes from 49% to 17% from the initial state (S/A/R/A = 7.3%/43.7%/25.6%/23.5%) to the final state (S/A/R/A = 4.5%/63.5%/12.5%/20.0%), and the content of aromatics was maximized to 63.5%. The gas layer formed by the aquathermolysis reaction in the reactor chamber was collected and analyzed by GC-MS spectroscopy. As a result, various hydrocarbon compounds such as ethylbenzene, octane and dimethylbenzene were detected.

• Clean Technology
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• v.27 no.1
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• pp.69-78
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• 2021

Vegetable oils, such as palm oil and cashew nut shell liquid (CNSL), are used as major raw materials for bio-diesel in transportation and bio-heavy oil in power generation in South Korea. However, due to the high unsaturation degree caused by hydrocarbon double bonds and a high content of oxygen originating from the presence of carboxylic acid, the range of applications as fuel oil is limited. In this study, hydrotreating to saturate unsaturated hydrocarbons and remove oxygen in mixed bio-oil containing 1/1 v/v% palm oil and CNSL on monometallic catalysts (Ni and Cu) and bimetallic catalysts (Ni-Zn, Ni-Fe, Ni-Cu Ni-Co, Ni-Pd, and Ni-Pt) was perform under mild conditions (T = 250 ~ 400 ℃, P = 5 ~ 80 bar and LHSV = 1 h-1). The addition of noble metals and transition metals to Ni showed synergistic effects to improve both hydrogenation (HYD) and hydrodeoxygenation (HDO) activities. The most promising catalyst was Ni-Cu/��-Al2O3, and in the wide range of the Ni/Cu atomic ratio of 9/1~1/4, the conversion for HYD and HDO reactions of the catalysts were 90-93% and 95-99%, respectively. The tendency to exhibit almost constant reaction activity in these catalysts of different Ni/Cu atomic ratios implies a typical structure-insensitive reaction. The refined bio-oil produced by hydrotreating (HDY and HDO) had significantly lower iodine value, acid value, and kinetic viscosity than the raw bio-oil and the higher heating value (HHV) was increased by about 10%.

• Analytical Science and Technology
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• v.25 no.6
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• pp.467-475
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• 2012

A gas chromatography-mass spectrometric (GC-MS) method was developed for determining 17 hazard compounds containing phenols, polycyclic aromatic hydrocarbons and pesticides in surface water. A 1.0 L surface water sample was placed in a separatory funnel and saturated with NaCl, and the solution was extracted with 40 mL of methylene chloride. Under the established condition, the lowest quantification limit was 1.0-10 ng/L and the relative standard deviations were less than 22%. The method was used to analyze 70 surface water samples collected from 35 regions in Gum-River. The samples revealed the compounds concentrations in the range of 1.1-26,604 ng/L. Maximum concentrations of compounds detected were not exceeded guidelines established in other countries. The developed method may be valuable for monitoring hazards in water.

• Geophysics and Geophysical Exploration
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• v.18 no.3
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• pp.125-132
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• 2015

The water saturation ($S_w$), which is very important to estimate hydrocarbon reserves in the reservoir, has been determined from resistivity index (RI) by using the Archie's formula. However, in many cases, it has been reported that n is not constant for a given formation and it could be varied with water saturation. In addition, it frequently happens that the line obtained by linear regression analysis on log-log scale does not pass through the origin. In order to overcome these drawbacks, we suggested a modified Archie's formula, which can handle almost all the RI vs. $S_w$ cross-plots whether the trend is straight or curved and whether it passes through the origin or not. We also demonstrated that how to determine conductivity exponent ${\mu}$, critical water saturation $S_c$, and saturation distribution factor b in the laboratory to use the modified Archie's formula. Since the modified Archie's formula takes into account pore structure, pore water distribution, and wettability of reservoir such as clean sandstone and carbonate rocks, it might improve field applicability.

• Transactions of the Korean hydrogen and new energy society
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• v.9 no.1
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• pp.8-15
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• 1998

The catalytic hydrogenation of carbon dioxide has been studied for the fixation of carbon dioxide to mitigate global warming problems, but it needed hydrogen, which the price is still high. Recently, the electrochemical reduction of carbon dioxide has been drawn attractions because carbon dioxide could be converted to the valuable chemicals such as methane, ethane and alcohols electrochemically in the electrolyte solution using a catalytic electrode. This system is simple because the water electrolysis and hydrogenation take place at the same time using the surplus electricity at midnight. In this work, a continuous electrochemical reduction system was fabricated, which was composed of the reduction electrode (copper or perovskite type, $2{\times}2cm^2$), reference electrode(platinum, $2{\times}6cm^2$), standard electrode(Ag/AgCl), and potassium bicarbonate electrolyte solution saturated with carbon dioxide. The quality and quantity of the products and reduction current were analyzed, according to the electrolyte concentration and electrode type.

• Korean Journal of Microbiology
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• v.32 no.2
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• pp.172-175
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• 1994

Xanthomonas campestris M12 carrying OCT plasmid which could dissimilate octane was able to utilize n-alkanes of eight to sixteen carbon atoms via the capacity of this plasmid. M12 strain could utilize terminal oxidation products of these primary, alkanes, alcohols, aldehydes and fatty acids but not hexanoic acid, adipic acid, pimelic acid and heptanal. This strain also biodegraded n-alkanes by monoterminal or diterminal oxdation of straight-chain fatty acids, and branched-chain alkane.